Had my hair bleached and a toner treatment used, as I do once every six weeks. My hair has fallen out in clumps. Any suggestion?

As above, I had my hair done yesterday and when washing the toner off, my hair fell out in clumps. I was devastated. I've had to have loads cut off and my hair is extremely thin. I'm terrified to touch it, never mind was it. I've been to a medical shop and purchased some hair vitamin tablets, but I really want to fix my hair and don't know how. I'm so upset, my hair looks so limp and lifeless. I just want it back and don't know what to do. It's so thin, there's nothing there.